Build dotfile management script from scratch

[RangHo]

For all these years, I kept shoving features after features into the poor little script, and it keeps breaking. I guess it is time to migrate to a proper dotfile management script. Here are the impressions of "dotfile utilities" that I tried:

• GNU Stow is what powers the current script thanks to its reliability, but it breaks when unmanaged symlinks pop up in HOME;
• Chezmoi deals with Git and version control very well, but unfortunately it dumps the entire Git repository into the system;
• Nix Home Manager is great that it manages everything in a nice, functional text file format, but its transactional nature makes me go back to plain old symlinks.

At this point, I need to build my own dotfile manager to satisfy my own needs. It must be able to:

• install individual components;
• install dependencies, both dotfiles and native packages;
• update repository and re-apply dependencies automatically;
• express the dotfile "package" in a good file format.

With this implemented, #9, #11, #12, #13 can be marked as not planned.

[RangHo]

See urijip for initial development efforts.

[RangHo]

Closing #9, #11, #12, #13, #23 since this issue replaces the management script altogether.